Effects of processing technique on the nutritional composition and antinutrients content of under –utilized food legume Canavalia ensiformis L.DC.

Jack Bean (JB) (Canavalia ensiformis) is an indigenous legume promoted in Tamilnadu as a green manure cover crop. It contains high protein but it is under - utilized due to the presence of 3, 4-dihydroxy-Lphenylalanine (L-Dopa) and other anti nutritional compounds. To improve its nutritional potential as a protein source, Jack bean was processed and evaluated for nutritional composition. Effects of processing at different methods like soaking, cooking and autoclaving on the contents of anti-nutritional compounds and crude protein were investigated. Raw beans contained high crude protein (29.8 g/100^-¹). Contents of ether extract; crude fibre and ash were 4.2, 7.37 and 4.48 g/100^-¹, respectively. Raw whole Jack bean contained L-Dopa (1.7 g/100^-¹) content. Other anti-nutritional compounds included total phenols 3.83 g/100-1, trypsin inhibitor activity (TIA) 378.3 TIU and tannins 82.5 mg/100^-¹. The present study also evaluated the changes of anti-nutritional factors of Jack bean by subjecting to soaking, autoclaving and cooking. Maximum reduction was observed in TIA, L-Dopa and Total free phenols with autoclaving, while the soaking and cooking decreases the levels of tannins. Autoclaving was more effective method in reducing trypsin inhibitor activity, polyphenols and L-Dopa than the various cooking treatments.